Pile elevating mechanism



F 1 I v J. BRASSEUR- FILE ELEVATING MECHANISM Original Filed Oct. 5,1928 "7 Sheets-Sheet 1 I ATTORNEY Feb. 1935. E. J. BRASSEUR PIL EELEVATING MECHANISM (11114 91 e1, ATTORNEY :Feb. 5, 1935,

E. J. BRAssEuR PIL' ELEVATING MECHANISM Original Filed 00L 3, 1928 7Sheets-Sheet 3' v QMQM'LAA ATTORNEY Feb. 5, 1935.

' E. J. BRA SS EUR 1,989,911

PILE ELEVATING MECHANISM Original Filed 0st. a. 1928 7 SheetS -Sheet 4INVENTOR- S w $1 ATTORNEY E. J. BRASS EUR v 1,989,911

FILE E LEVATING MECHANISM Feb. 5, 1935;

Original Filed 001; 5, 1928 '7 Sheets-Sheet 5 IIINVEINTCIJR so ATTORNEYE. J. BRAs'sEuR FILE; ELEVATING' MECHANISM 7 Sheets-Sheet 6 OriginalFiled Oct. 3, 1928 Q wm "w n o m% Mmw \m Hm m l iiidd:

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FILE ELEVATING MECHANISM Oniginal Filed Oct. 3, 1928 7 Sheets- Sheet 7 HINVENTOR BY 5k Gmtwx e ATTORNEY lllllllllll lll Patented Feb. 5, 1935FILE ELEVATING MECHANISM Ernest J. Brasseur, Chicago, 111., assignor toA. B. Dick Company, Chicago, 111., a corporation of Illinois Originalapplication mm: 3, 1928, Serial No. 309,9 41. Patent No. 1,843,118.Divided and this application April 19', 1930, Serial No. 445,797

4 Claims. (01 271-62) form pressure, which is sensitive and alertin Thisinvention relates to pile elevating mechanism and particularly toapparatus of this character adapted for use in connection with stencilduplicating machines.

5 This application constitutes a division of my copending applicationSerial No. 309,941 entitled Improvements in sheet feeding apparatus,filed October 3, 1928.

Thisinvention is concerned with the provision of mechanism adapted toautomatically raise a platform structure so as to maintain sheets orother material supported thereon at a constant level during feeding ortreating operations, and

especially to the provision of such mechanismadapted for associationwith printing and stencil duplicating'machines whereby greater speed,accuracy and positiveness of operation may be attained.

In order that the feeding device of a stencil duplicating machine mayoperate effectively it is necessary that the top of the sheet pile fromwhich the sheets are consecutively removed be maintainedat the properfeeding level at all times during operation. The feeding device used inconnection with such machines generally move through a fixed orbit orpath, and if the top sheet of the stack is not in exactly the properposition the-feeding device will engage the sheet indifferently, andoften feed the sheet improperly.

This situation requires that the mechanism for elevating the sheet pilealways maintain the. top of the sheet pile at precisely a uniform levelunder all conditions of.operation. Slow and unreliable stencil printingin the past has been largely attributableto the inaccurate, improper anduntimely elevating of the top sheet of the sheet pile. Such mechanismshave furthermore lacked sensitiveness and alertness in responding to therequirements of the sheet feeding device. Delicate and complicatedparts, which frequently break down and become out of repair, are furtherdefects of prior mechanisms heretofore used.

-- An object of my inventionis' to produce an improved pile elevatingmechanism adapted espe- 5- cially for use in connection with printingand duplicating machines, by means of which a greater output per unit oftime can be obtained from the machine than heretofore and a betterquality of responding to the requirements of the feeding device, andwhich is fm'thermore provided with means for making various adjustmentsof the elevating mechanism to attain effective feeding of sheets ofvarious qualities and characteristics.

A further object of my invention is to provide an improved tableelevating mechanism especially adapted for stencil duplicating machinesincluding a table adapted to support a sheet pile and an elementsensitiveto the top level of the sheet pile for throwing table raisingmeans into operation when'the sheet pile fallsbelow a predeterminedlevel, so that the top of the sheet pile is always maintained at theproper feeding level regardless of the number of sheets on the table.

A further object of my invention is to provide a pile elevatingmechanism adapted for use in connection with stencil duplicatingmachines which is strong, sturdy and of few moving parts, which ispositive and rapid in its operation, which will give a greater output ofbetter work, and v which is not 'apt to get out oforder.

Other objects of this invention will be in part obvious and in partpointed out hereinafter.

The pile elevating mechanism forming the subject matter of thisinvention may be operatively associated with. any machine which requiresthat the material operated upon be maintained at a uniform level. I,therefore, contemplate using my mechanism with any form of printing,cutting, trimming or scoring machine with which it may be adaptablyassociated. My mechanism, however, is especially adapted for use inconnection with stencil duplicating machines of the type known as themimeograph.

For purposes of illustration only, I have shown my pile elevatingmechanism as associated with a stencil duplicating machine. Inaccordance with this invention, my pile elevating mechanism comprises atable or platform adapted to support a sheet pile and is so positionedthat sheets from the sheet pile are moved directly into engagement withthe feed rollers of the duplicating machine. Mechanism is provided forraising the sheet pile supporting table both manually and automatically.The table rests upon two pairs of lever arms or legs, each pair fixed toa rotatable shaft. The shafts are geared together so that. as one of.the shafts is rotated the table platform may be raised or lowered.Manual movement of a hand lever attached to one of the shafts raises orlowers the table.

The table is automatically raised in easy stages as sheets are fed fromthe sheet pile. A ratchet segment fixed to one of the table raisingshafts is adapted to be engaged by a reciprocating pawl to move the gearsegment-downwardly, raising the table. Reciprocating movement is givento the pawl by a rotatable cam fixed to a moving shaft of the stencilduplicating machine, and a train of pivoted arms. The reciprocating pawlis normally'spring-pressed out of engagement with the ratchet segmentand is thrown into'engage ment with the ratchet segment. only when thetop of the sheet stack falls below a predetermined feeding level.

A device is provided for throwing the pawl into engagement with thetable raising ratchet segment when the sheet pile falls below thepredetermined feeding level; The pawl is sustained in ratchet engagingposition until the table has been raised sufliciently to move the top'of the- A releasable latch device automaticallyretains.

the table at any elevation to which, it is raised. Release of the latchpermits the table to drop of its own weight to its lowermost position.

In order that a clearer understanding, of this,

invention may be had, attention is hereby directed to the accompanyingdrawings, forming a part of this application and illustratingcertainpossible embodiments of this invention.

7 Referring to the drawings, Figure 1 is a side elevation of. my pileelevating mechanism associated with a stencil duplicating machine,showing the various control devices of the machine;

Figure 2 is a side elevation of my pile elevating mechanism andassociated stencil duplicating machine, taken on the opposite side ofthe. ma.- chine from that shown in Figure 1, showing certain workingelements thereof; 1

Figure 3 is a'vertical cross-sectional view taken longitudinally of themachine, showing certain working elements interior of the machine;

Figure 4 is a horizontal cross-sectional view of my mechanism andassociated stencil duplicating machine,- taken on line 44 of Figure -3and illustrating more in detail certain operative elements thereof;

Figure 5 is an enlarged-fragmentary plan view 7 of the machine withcertain parts broken away to illustrate more clearly certain operativeelements thereof;

Figure 6 is an enlarged view of a part of the table raising mechanismillustrating the position of the parts at one stage of the raisingoperao Figure 7 is a similar view of a part of the tableof my invention,showing the pawl means normally latching the sheet supporting tableagainst downward descent and connecting mechanism for moving the pawlout of latching position to permit the table to descend.

Similar reference characters designate the parts throughout the several.views of the drawings.

Although my pile elevating mechanism is adapted for use with variouskinds of machines as above noted, it is especially adapted for mainconnection with stencil duplicating machines, and for purposes ofillustration therefor, I have shown in the drawings my mechanismassociated with such amachine.

Referring to the drawings, and more particularly to Figures 1, 2 and 3,the machine generally consists of a base 1 on which side frames 2 and 3are erected. A stencil duplicating drum 4 is mounted for rotation insuitable bearings provided in the side frames2 and 3. The drum isadapted to carry a stencil. sheet secured about the cylindrical surfacethereof in the usual manner; The drum is rotated by means of a crank5'secured to a pinion 6 which meshes with a gear '7 fastened to one headof the drum. A pressure roller 8 is carried on pivoted arms 9 in theusual manner and drawn toward the drum by springs 10.

A shaft 11 is mounted for rotation in suitable bearings in the sideframes. A sleeve 12 carrying sheet forwarding sectors '13 is looselymounted on the shaft 11. Sectional rollers 14 are fixed to a shaft 14'.The 'ends'of-the shaft 14' are positioned in vertical guideways in theside frames" 2 and 3, permitting a raising and lowering movement of therollers.- Sectors 13, coacting with sectional rollers 14 fixed to shaft14', operate to forward sheets between them to the line of contact ofthe drum-and pressure roller. The sectors 13 rotatev at the same surfacespeed as that of the drum.- The radius of the drum and'the sectors issuch that the sectors make three revolutions during one'revolution ofthe drum. The sectors are driven by suitable gearing, comprising gear 15secured to shaft 11, connected by a train of gears 16 to the pinion 6.The'gear 15 is secured to a gear 17 which meshes with a gear 18rotatable on a shaft 19. The gear l8 is connected to a gear 20 alsorotatable on shaft 19. Gear 20 is adapted to mesh with a pinion; 21which is fastened to the sleeve 12 carrying the signed to feed singlesheets successively to the sheet forwarding devices consisting of thesectors l3 and roller 14. The sheet forwarding devices then cooperateonce during each revolution of the-drum to forward the sheet so fed tothe drum 1 23 and 24, suitably Journaled on the side frames 2 and 3,each have a pair of oppositely extending legs or lever arms 25 securedthereto. The free end of each leverlarm is provided with a roller 26adapted to ran along a track 27 on the under side of the table; Thetable platform rests upon the rollers 26 and is supported entirely bythe two pairs of legs or lever arms 25. Segment gear 28 secured to shaft23 meshes with segment gear 29 secured to shaft 24. A hand lever 30 issecured to one end of shaft 23. It is seen that by turning the handlever both shafts will be 'rotated, thus manually raising or loweringthe table supporting the sheet pile. The mechanism for automaticallyraising the table platform will be described hereinafter. A verticalpost 31 on each side of the table platform guides the same initsvertical movement. Each post is secured to lugs 32 projecting from theside frame and extends through an aperture in the table platform.-

A vertical wall member 33 forms an abutment for the sheet pile at oneend ofithe table. A slidable abutment plate 34 at the other .end of thetable is provided, which may be moved into abutting relation with theother end of the sheet pile and locked in abutting position by means ofa suitable latch 35. Sheets of various lengths can thus be accommodated.

Successive sheets are' fed from the sheet pile by a reciprocatingfeed-shoe. The feed-shoe, comprising generally a sheet gripper element36 and a supporting frame 37 therefor, is supported on a frameworkextending horizontally over the sheet pile. A pair of channel shapedsupports or frame members 38, one positioned at each side of the table,extend approximately the full length thereof. Each channel support iscarried by lever arms 39 and 40 pivotally secured thereto. Lever arms39, one pivoted to each of the channel members, are secured to a shaft41 journaled in the side frames 2 and 3. Lever arms 40, one pivoted toeach of the channel members, are secured to shaft 42 journaledin theside frames 2 and 3. By rotating either one of these shafts it is nowseen that the channel supports 44 will be given 2. raising and loweringmovement in reference to the sheet pile, but will nevertheless alwaysremain parallel thereto.

Each channel support carries a bar member or arm 43 provided withrollers adapted to roll within the channel support. A pair of elongatedslots 44 are cut in each of the channel supports. Each bar member 43carries a pair of headed studs 45, each of which extends through one ofthe slots of the associated channel support, thus slidably holding thebar member in position. Each bar member has a rack bar 45 securedthereto to which the feed-shoe can be adjustably secured. The barmembers are given a reciprocating movement along the channel members bythe to and fro rotation of a shaft 47 journaled in the side frames 2 and3. This is effected by a pair of lever arms 48 secured to the shaft andconnected to their respective bar members by means of a link 49. Thefeed-shoe maybe locked in various positions along the bar member, andthus carried along' therewith during the reciprocating movement. Thefeed-shoe is raised and lowered into-and out of contact with the sheetpile by the ra sing and lowering movement of the channel supports.

A pair of coil springs 50, one secured to each of the channel membersand one of the side frames, normally pull the channel members downwardlyto carry the feed-shoe into contact with the top sheet of the sheetpile. The channel members are raisedagainst the action of the springs bymechanism connected to a moving part of the machine. As shown in Figure2, a cam member 51 is secured to shaft 11 and rotates therewith. A riderarm 52 secured to shaft 42 carries a roller 53 on the free end thereof,adapted to ride on the cam periphery of the cam member. Shaft 11' andcam member fil make one revolution during one revolution of theduplicating drum. Rotation of the cam member raises the channel supports38' and feed-shoe against the action of springs 50. The cam member is soshaped that the channel suppoi'ts'are held in maximum raised and maximumlowered position for an interval during each rotation of the cam. As isevident, the roller 53 is held in resilient contact with the camperiphery of the cam member 51 by the action of springs 50.

Elasticity of operation is thus obtained and rattling of the partseliminated.

Bar members 43 are also reciprocated by mechanism attached to a movingpart of the machine.

A second cam member 54 is secured to rotating shaft 11, and reciprocatesa rider arm 55 associated therewith. As shown more clearly in Figures 6and 7, the rider arm has an elongated aperture 56 in one end thereof,through which shaft 11 extends. A roller 57 is secured to the side ofthe rider arm and so arranged as to ride over the cam periphery of thecam member. A heavy coil spring 58, secured to the free end of the riderarm. and to the side frame of the machine, holds the roller in constantcontact with the cam periphery of the cam member. A lever arm 59 securedto shaft 47 is pivotally connected to the rider arm. Lever arms 48connected to the bar members 43 are also secured to shaft 47, asheretofore explained. It is now seen that rotation of the cam member inone direction moves the bar members and feed-shoe rearwardly. The cammember is'so shaped that the bar members are held in maximum rearwardand maximum forward position for'an interval during each rotation of thecam member. Coil spring 58 tends to draw the bar'members forwardly. Thusby the coaction of rotating cam member 54 and coil spring 58 the barmembers and feed-shoe are given'a to and fro reciprocating movement. Itis also seen that cam member 51 connected to the ascending anddescending channel supports, and cam member 54 connected to thereciprocating bar members are secured to the same rotating shaft 11. Thecam members are of such shape and so positioned in relation to eachother as to attain the proper sequence of movements to move thefeed-shoe generally along a predetermined fixed path.

During the feeding of the top sheet from the sheet pile, it is essentialthat the remaining sheets be held against movement or disturbance. Tothis endI provide a clamping mechanism which is movable off from thesheet pile to permit the withdrawal of the top sheet from out of itsinfluence but movable into clamping engagement with the remaining sheetsas the top sheet is moved forwardly off the sheet pile. Referring moreparticularly to Figures 3, 4 and 8, I provide a plurality of bar members60 (four being shown in Figure 8, although I do not limit myself to thisnumber), each having a pair of slots 61. A headed stud element 62,secured to the stop plate 33, extends through each slot, thus slidablyretaining the bar members on the stop plate and permitting verticalmovement of each in relation to the sheet pile. Each bar member isprovided with a laterally projecting lip porticn 63 adapted to overhangthe forward edge of the sheet pile and rest upon the same, as clearlyshown in Figures and 6. A downward pull is exerted on each bar member bya coil spring 64 secured at one end to a pin 65 projecting from the barmember and at its other end to stud element 62, so that the lip portionthereof normally rests upon the sheet pile with resilient pressure.

Means are provided, synchronized with the movement of the feed-shoe, forraising lip portions 63 oil the sheet pile. 'A cam member 66 is securedto shaft 11 and rotates therewith. A rider lever 67 secured to shaft 68carries a roller 69 at its free end which is adapted to ride on the camperiphery of the cam member. A pair of lever arms 70; secured to shaft68, carry a rod' 4 80 is provided with a laterally extending footportion 72 under which rod 71 extends. Cam mem-' ber 66 is so shaped asto cause lever arms '10 to be swung upwardlyto raise the bar members and5 move the lip portions 83 thereof of! the sheet pile periphery of thecam member by the action of spring element '73 secured at one end toside frame 3 and at its other end to lever arm '74 secured to shaft 68.Cam member 66 secured to shaft 11 makes one rotation during one rotationof the stencil duplicating drum. Cam member 66 is so shaped as to raisethe lip elements 63 off the sheet pile as the feed-shoe is being loweredinto contactposition with the top sheet. The lip elements remain inraised position during the sheet retracting operation. The lip elements63 are then returned to clamping engagement with the remaining sheets ofthe sheet pile by the action of the springs 64. The front edge of thetop sheet slides over the lip elements as the sheet is moved forward bythe feed-shoe. of rotating cam 66 and coil springs 64 each bar member isgiven a vertical reciprocating movement as each sheet is fed,alternately raising the lip portions 63 off from and into clampingengagement with the sheet pile.

The automaticmeans for raising the table will now be described. A longlever arm '75, as shown in Figure 2, provided with a ratchet segment '76on the end thereof, is secured to the table raising shaft 23. A pawlmember .77, having a reciprosegment to move the same downwardly to raisethe table. An arm 78, pivoted at one end to a lug 79 secured to the baseof the machine, is pro- Thusby the coaction' nism for the pawl memberinto engagement with the ratchet segment when the top of the sheet-pilefalls below a predetermined level, and for holding the pawl in ratchetengagement until the predetermined level is restored. As shown inFigures 5 and 8, one of the bar members 60 is provided with a laterallyprojecting arm 86. on which the end of lever 8'! secured to shaft.88 isadapted to rest. Shaft 88 may be suitably journaled in the side frame 3.

V A rider arm 89 Journaled on shaft 88 carries a roller 90 adapted toengage a cam element 91 secured to the pawl member 77. Rider arm 89 issupported in laterally extended position by a carrier arm 92 secured toshaft '88. -The outer end of the carrier arm, as shown in Figure 2,

is provided with a pair of ears 93 each carrying an adjusting screw 94.The rider arm extends between the ears 93 and is itself provided with 9.lug 95 with which the adjusting screws cooperate to vary the contactrelationship between roller 90 and the cam element 91 of the pawl willlever arm 87 swing downwardly sufficiently to permit the rider arm 89 toactively engage the cam element 50 as to swing the pawl member intoengagement with the ratchet segment. One or two reciprocatingengagements of the pawl memvided with a slot 80 at its other end. A studeleber with the ratchet segment is generally s m.

ment 81 adjustably secured in a slot 82 in rider arm 52 extends throughthe slot in arm 78. Pawl member '77 is pivoted at its lowerend to themidsection of arm 78. The pawl'member is normally held'out of contactwith the ratchet segment by the action of spring element 83, for reasonswhich vill hereafter appear. It is seen that as rider arm 52 isreciprocated by the rotation of cam member 51, arm '78 supported at oneend by the arm 52, is also given a slight reciprocating movement, whichin turn reciprocates the pawl. By

' manipulating stud element 81, the reciprocating distance traveled bythe pawl arm can be adjusted and fixed,- and thus varythe distance thetable platform, is raised by one stroke of 'the pawl.

It is desirable to lessen the effort required to raise the table as muchas possible. With this end in view, I provide a heavy coil spring 84se-' t9 raise the table.

. Since the raising and lowering and the to and fro reciprocatingmovement of the feed-shoe is fixed and uniform, it is essential foreffective feeding that the 'top of the sheet pile always rethoughreciprocating, is held out ofengagement with the platform raisingratchet segment 76 by the spring element 88. I have provided mechacientto raise the table platform so that the sheet pile is again at thepredetermined proper feeding level. Lever arm 8'7 is then raised by thebar member 60 against the action of coil spring 96, also raising therider arm 89 slightly so that spring element 83 can throw the pawlmember out of operative engagement with the ratchet segment. Theposition of the roller 90 in relation'to the cam element 91 can bedelicately adjusted by screws 94 so that the removal of a very fewsheets from the sheet pile will operate to cause the rider arm 89 tothrow the pawl member 77 into operative engagement with the. ratchetsegment to raise the table. The teeth of ratchet segment 76 arepreferably small and fine, so that with each reciprocating engagement ofthe pawl member '17 therewith, the table may be raised almostinfinitesimal amounts. The top elevation of the sheet pile is thusmaintained practically constant during the feeding of successive sheetstherefrom. By means of this arrangement, the

I pressure grip of the feed-shoe on the successive.

sheets being fed is invariably the same.

' Means are provided for releasably retaining the table atthe elevationto which it has been manually or automatically raised. A pawl member 97adapted to engage the teeth of ratchet segment '76, as shown in Figures2, 6 and 7, is journaled on a stud screw 98 fixed to the sidev plate 3.Pawl member 97 is normally held in engagement with the teeth of theratchet segment by the action of spring element 99, thus preventing theratchet segment from swinging upwardly with resultant lowering of thetable. It is now seen that pawl members 77 and.97 operate conjunctivelyto raise the table and retain the table in the position to which it israised.

Means are provided for moving pawl member 97 out, of engagement with theratchet segment to permit the table platform to drop or lower from itsown weight. As shown in Figures 1 and 2, a thumb lever 100 is secured toone end of a shaft 101 journaled in the side plates 2 and 3.

YA small crank lever 102, secured to the other end the sheet pile isbelow the predetermined feeding level. The table raising pawl member 77would then be in engagement with the teeth of the ratchet segment,preventing any lowering of the table platform. It would then benecessaryto also swing pawl member 77 out of engagement with the teethof the ratchet segment. Accordingly, I have provided the table raisingpawl member 77 with a clip element 104, as shown in Figures 6 and 7.Clip element 104 overhangs the end of pawl member 97 and is adapted tobe engaged thereby (as shown in Figure 7) when the pawl member is swungback sufiiciently, thus carrying table raising pawl member with it andout of engagement with the ratchet segment. It is now seen that bysimply manipulating thumb lever 100 both pawl members 77 and 97 can beswung out of engagement with the ratchet segment.

Means are provided for releasably holding retaining pawl member 97 outof engagement with the ratchet segment. I accordingly provide a latchmember 105, shown in Figures 1 and 9, journaled to a stud screw 106projecting from the side frame 2. The free end of latch member 105 isnotched so as to provide an abutment portion 107. Thumb lever 100 isprovided with an upwardly extending arm 108. The latch member normallyrests on the end of arm 108 and is resiliently retained thereagainst bythe action of spring element 109. By referring more particularly toFigure 9, it is seen that when latch 105 is disengaged from arm 108, asshown in full lines, retaining pawl member 97 is spring-pressed intoengagement with the ratchet segment. By pressing downwardly on thumblever 100, pawl member 9'7 may be swung out of ratchet engagement. Latch105 will then drop down so that abutment portion 107 prevents the returnof the pawl member into ratchet engagement. Further rotation of thethumb lever 100 swings the retaining pawl member 9'7 into contact withthe clip element 104, as shown in'dotted lines, Figure 9, moving tableraising pawl member '7 7 with it and out of ratchet engagement. Pins 110and 111, projecting from side frame 2, limit the movement of the latchmember within proper bounds.

Pin 112, also projecting from side frame 2, limits the rotation of thumblever 100. The latch member may be provided with a knob 113 projectingtherefrom, by means of which it may be raised. Thus by simplymanipulating thumb lever 100, the table can be dropped down at will. Thetable platform can likewise be raised at will by manipulating hand lever30. When the machine is'in operation, the table is automatically raisedby the reciprocating raising pawl '77 thrown into engagement with thetable raising ratchet segment '76 when the call is made by the barmember 60 resting on the sheet pile.

When the table has been raised to a predetermined raised position, aroller 114 automatically operates to throw the retaining, pawl 97 out ofengagementwith'the ratchet segment, permitting the table to dropto;1ower most position. As shown more clearly in Figure 7, .theroller114, carried by the ratchet segment, is adapted to roll against the camsurface of pawl97.as the ratchet segment is moved downwardlyandgfinallythrows the pawl out of ratchet engagement. erm 108 of thumb lever 100,as heretofore'described, is then moved over sufficiently to,permitabutment portion 107 of 1atch'105 to drop into en gagement withthe end of the arm,- locking the pawl in out of ratchet engagingposition. The table then drops by reason of its own weight to lowermostposition. It is preferable to so position roller 114 in relation to thepawl that thepawl is moved out of ratchet engaging position permittingthe table to drop while there are still a few sheets remaining on thetable; thus protecting the feed-shoe and other operative parts frominjury due to continued raising of the table.

Vertical guide bars 115, one disposed on'each side of the sheet pile,retain the sheets in a vertical stack, and guide them to the feed roller116 of the machine. The guide bars rest on the table platform and movevertically therewith. Each guide bar is slidably supported in a framemember 117 carried by a horizontal bar 118 attached to the side frames 2and 3 of the machine. The supporting frames 117 may be moved to anyposition along the bar 118 andclamped thereto by clamping screw 119. Bythis arrangement, the guide bars may be moved to any position toaccommodate therebetween sheets of various widths.

The operation of my. pile raising mechanism and associated parts of thestencil duplicating is placed upon the table platform. Sliding plate 34is then moved into abutment against one end of the sheet pile, the otherend of the sheet pile abutting against the wall member 33. Guide bars115 are then moved into abutment against the sides of the sheet pile.All the sheets are now retained in a vertical stack or pile,'as shown inFigure 3. Hand lever 30 is then manipulated to raise the platform untilthe top of the sheet pile is raised to. the approximate proper feedinglevel.

The entire sheet feeding mechanism and stenciling mechanism is driven bythe turning of crank arm 5 or a motor (not shown) in place thereof. Withthe turning of crank arm 5*the table raising pawl 77 is reciprocated bythe train of mechanism heretofore described. The stroke or the distancetraveled by one reciprocation of the pawl member 77 is preferably slightso that the table is raised a very small amount only at each stroke.Pawl member 77 is pressed forwardly into engagement with the ratchetsegment against the action of spring element 83 by I reciprocating pawl77 into operative engagement with the ratchet segment. The tableplatform is *flthen raised by very gradual degrees until the lipelements have been raised by the sheet stack sumfciently to release thepressure of rider arm against the cam element 91 permitting springelement 83 to throw the pawl member out of ratchet engagement. The tableplatform is normally retained in raised position by the pawl member 97and may be dropped or lowered at will by merely manipulating the thumblever 100 and latch 105, as heretofore described.

While my pile elevating mechanism is especially adapted for use inconnection with printing and stencil duplicating machines of the typeknown commercially. as the mimeograph, it is understood, however, that Ido not limit my mechanism to this use alone, and that it may also beused in connection or association with any machine, receiver or devicerequiring that sheets or other material operated upon be maintained at aconstant level.- Further, this invention'is not restricted to theprecise construction which has been described above for the purpose onlyof illustrating the invention. Accordingly, as many changes could bemade in the above construction and various different embodiments of thisinvention could be made without departing from the scope thereof, it isunderstood that all matter contained in the above description or shownin the accompanying drawings shall be interpreted as illustrative andnot in a limiting sense.

What I claim is: 1. In combination with sheet feeding apparatus of thecharacter-described, a table support for a sheet pile, and meansfor'raising the table sup-. port as successive sheets are fed from thesheetpile so as to maintain the sheet pile at the proper feeding level,said'means including a ratchet segment operatively connected to thetable support, a pawl having a reciprocating movement normally out ofengagement with said ratchet segment, said pawl having a cam portion, ashaft, an arm fixed to said shaft, a rider element adjustably secured tosaid arm and adapted to engage said cam portion to movethe' pawl intooperative engagement with the ratchet segment, and means operatively Iassociated witlnthe sheet pile to rotate said shaft as successive sheetsare fed from the sheet pile,.

said means including a ratchet segment operatively connected to thetable support, and reciprocating means for engaging said ratchet segmentto raise the table support, a pawl'member-normally in engagement withthe ratchet segment to hold the table support in successive raisedpositions and means on said ratchet-segment for throwing the retainingpawl out of engagement therewith when the table support has reached apredetermined maximum level.

3. Insheet feeding apparatus, the combination with a table support for asheet pile, automatic means for raising said table support including aratchet segment operatively connected to the table support andreciprocating means adapted to engage said ratchet segment to raise thetable support, a retaining pawl normally in engagement with the ratchetsegment to hold the table support in successive raised positions, and

a roller carried by said ratchet segment adapted to engage a cam surfaceof said retaining pawl to throw the same out of ratchet engagement whenthe table support has reached a predetermined maximum level.

4. In an apparatus for feeding successive sheets from a sheet pile, atable support for the sheet pile, means for raising the table support assuccessive sheets are fed from the sheet pile so as to maintain thesheet pile at the proper feeding level, and vertical guide bars restingon said table, said guide bars being laterally adjustable to accommodatethe sheet pile positioned therebetween and to retain the sheets in avertical stack.

ERNEST mnnassntm.

